I'm using numbers from 95BLKMAX (many many thanks) to try and narrow down which turbo I want to use. The only thing I'm not sure on right now is if I have to take the fact that it is a RMT into account when choosing. (Ok so that's not the only thing, but it's what's on my mind right now.)

What I mean is this; Should I input the numbers and choose the perfect turbo for my engine based on a front mount application and then stick it in the back?

Or do I choose a turbo that's slightly smaller to offset the lag time? For example, I was looking at these 2 turbos


http://www.turbobygarrett.com/turbob...7_452233_5.htm


http://www.turbobygarrett.com/turbob...R_707160_9.htm

The first one is a better fit according to the numbers from 95BLKMAX, but would the second one would spool quicker and offset lag?

If I choose the smaller one I feel like the thing's going to spool at 4k and die off before 6 and causing a restriction

And if I choose the larger one I'm afraid I'm going to have ungodly amounts of lag and have a turbo that's suited for highway pulls. Which is not what I want.

Thanks in advance for any input

 

**guys these #s of mine he's talkin about are from tables that I made based off of http://www.junkyardturbos.com/101_1.html ** Make those tables yourself if you want my gibberish to make sense, lol.

Are you sure you're reading my tables right? Because that 1st turbo is waaaaaay too small. On my table, for your engine at 10psi, I got a pressure ratio of 1.68 at a lb/min at redline of 33.1 after removing ~15%. With that said, look at those #s on that 1st turbo's compressor map. Its still in the 70s % isles but obviously its past its "most efficient" range basically by 4500. Either way, I could have told you just be you giving me the specs that it was small, lol. This turbo would be great on SRT4s, not for us.

OMG! the 2nd one is a little pee shooter! By 4500 (on my table I have a 33.1 lb/min at that rpm) you're already off the compressor map!

When choosing a turbo for RMT, you do not take into account it being in the back, becuase once the pipes are wrapped- as we proved with streetz's RMT setup, who's turbo was PREVIOUSLY mounted on another VQ30DE 4th gen maxima, the "extra lag" was only exactly 100 RPM. That is less of a difference than hot day/cold nite makes on spoolup, not even noticeable.

You want to know what kind of turbo to get? Well where do you want your powerband, and ultimately, how much power do you want to make? We'll tell you from there what size turbos to look at. Then the compresor map narrowing-down to the right turbo for your requirements is up to you.

 

ok I guess I was undershooting a little bit, still learning....go bigger then!

http://www.turbobygarrett.com/turbob...6_452159_1.htm



http://www.turbobygarrett.com/turbob...R_714568_3.htm

Better?

 

The overall spoolup RPM range might not be affected so much mounting a turbo in the back, but transient response will. So in that sense a RMT does change things if off-on throttle response is your thing (not just @ WOT either). That should be taken into account, IMO.

 

I'm not sure I understand, are you saying that when I change the throttle suddenly the turbo may react with a delay? Such as not having instant response when I floor it?

I really like the first turbo from my second post but I'm still looking, Man there are alot of turbos! Basically I'm looking for something that will reach a good amount of boost by about 3500 to 4000 RPM but still pull strong till 6500. I don't know if that's realistic but I really want something that will spool at 4500 at the highest.

let me know what you think.

thank you guys for helping me out, the turbo itself is the heart of the project and I don't want to screw that up

 

something else to bring up (been going thru my brain the past week) with a RMT setup, you need an oil pump in the back in order to feed and drain oil from it. If you choose a turbo needing water also you'll need an additonal pump to feed coolant back to the turbo also. I'm not sure if anyone has done this before but if not this will be needed also. If you were to go with a turbo that requires water also.

something else to keep in mind when selecting a turbo for this specific style of setup

 

This is a very good point u bring up. in an oil AND water cooled turbo, one would need 2 pumps. one for oil, the other for water. So keep things simple, oil only, RMT doesnt get hot enough anyways to needing all that cooling.

 

I'd just save all that cold piping and oil pump and just throw it in the engine bay with a nice forward y-pipe and get good response and great power with reduction in piping!

 

and spend the extra $800-$1200 to do the custom feedpipes, downpipe, and catback all mandrel bent that will be needed to do that? I'd use that $ for something more uselful thank you very much....

He's not asking if someone thinks he should install it in the front or not.... simply what turbo he should use. That's not what this thread is about.

 

Agreed the turbo should be selected whether it be front or rear. If properly done as RMT, it will be just as effective as the front (WOT power, and spool up time), response i slightly agree it will be better in the front, however I doubt it would be noticeable. In my case my turbo starts showing positive pressure at about 2900, unless i brake boost then i get boost 2kish or earlier. in my opinion, my turbo is perfect (for me that is), i can drive weeks without going into boost and just being civilized yet i can give it slightly more gas and get into boost. its a t04b. .69ar turbine, .60ar compressor.

 

T04b is an older line of garrett turbos right? I googled it and found a few used ones. If I looked up a turbo with those same specs by garrett or masterpower or whoever, would I get close to the same performance as your turbo?

 

you might. All engines operate differently and your mods would make your engine perform differently than streetz. But if you have the same vq30de its a very good chance it will operate close to the same as his, assuming your setup is identical to his

with proper turbo selection and proper installation an RMT can be just as effective as a front mounted turbo setup. One of the Beauties of the RMT setup is a lot of money is saved with piping and welding. If you know someone who can weld for cheap and get piping cheap then by all means. But budget wise, you cant ignore the RMT setup, especially now that its been proven